Cook the pumpkin. Cut about 8 oz/ 230 g of pumpkin into cubes. Place in a small pot, add ¼ cup water, and cook, covered, for 10–15 minutes until soft, occasionally stirring. Blend and cool. Measure the needed amount for the recipe.
Streusel:
Make the streusel: Combine flour, both sugars, and cinnamon in a medium bowl. Rub in the soft butter until coarse crumbs form (I do it with my hand – I find it works best). Refrigerate the mixture until ready to use.1 ¼ cups all-purpose flour + ⅓ cup brown sugar + 3 tablespoons white sugar + ½ teaspoon cinnamon + ½ cup unsalted butter
Muffins:
Preheat the oven to 360°F / 180 °C and line the muffin pan with paper liners.
Dry ingredients: Mix flour, cocoa, cinnamon, baking soda, baking powder, and salt. Set aside.1 ¾ cups all-purpose flour + ¼ cup unsweetened cocoa powder + 2 teaspoons cinnamon + 1 teaspoon baking soda + 1 teaspoon baking powder + 1 pinch of salt
Wet ingredients: In another bowl, mix the pumpkin purée and both sugars until smooth. Add the eggs and mix until fully incorporated. Add the oil and buttermilk and mix until well combined.¾ cup pumpkin puree + ⅓ cup light brown sugar + ⅓ cup granulated sugar + 2 large eggs + ½ cup neutral-tasting oil + ⅓ cup buttermilk
Add dry ingredients: Carefully, fold the dry ingredients into the wet ones until just combined. Use a spoon or a spatula and don’t overmix.
Add streusel: Fill the prepared muffin cups evenly with batter. Top them with the streusel.
Bake the muffins: Bake the pumpkin muffins for 20-25 minutes or until a toothpick inserted into the center comes out clean. If you want to glaze them, do it as soon as you remove them from the oven.
Lemon glaze:
Glaze: Mix the sugar with 1 tablespoon of lemon juice. Add a few more drops of lemon juice if needed. The glaze should be thick yet pourable.½ cup confectioner's sugar + 1 to 1 ½ tablespoons lemon juice
Drizzle the glaze over the streusel muffins immediately while they’re still hot.
Let the muffins rest in the pan for 10 minutes. Transfer to a wire rack to cool completely.
Notes
Measurements: Always use a digital kitchen scale in baking; it guarantees the best results.